title: Quantitative liver 31P magnetic resonance spectroscopy at 3T on a clinical scanner.
abstract: OBJECTIVE
  The aims of this study were (i) to establish a robust and fast method to quantify hepatocellular phosphorus compounds in molar concentration on a 3T clinical scanner, (ii) to evaluate its reproducibility, and (iii) to test its feasibility for a use in large cohort studies.
  
  
  METHODS
  Proton-decoupled (31) P magnetic resonance spectroscopy of liver (31) P compounds were acquired on 85 healthy subjects employing image selected in-vivo spectroscopy localization in 13 min of acquisition at 3T. Absolute quantification was achieved using an external reference and double-matching phantoms (inorganic phosphates and adenosine triphosphate (ATP) solutions). Reproducibility of the method was also examined.
  
  
  RESULTS
  This method showed a high intra- and interday as well as inter- and intraobserver reproducibility (r > 0.98; P < 0.001), with a high signal to noise ratio (SNR) (i.e., mean SNR of γ-ATP: 16). The mean liver concentrations of 85 healthy subjects were assessed to be 1.99 ± 0.51 and 2.74 ± 0.55 mmol/l of wet tissue volume for Pi and γ-ATP, respectively.
  
  
  CONCLUSIONS
  This method reliably quantified molar concentrations of liver (31) P compounds on 85 subjects with a short total examination time (∼25 min) on a 3T clinical scanner. Thus, the current method can be readily utilized for a clinical study, such as a large cohort study.
authors.affiliation: Institute of Clinical Diabetology, German Diabetes Center, Düsseldorf, Germany.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Laufs
authors.forename: Roshan
authors.initials: R
authors.lastname: Livingstone
authors.forename: Bettina
authors.initials: B
authors.lastname: Nowotny
authors.forename: Peter
authors.initials: P
authors.lastname: Nowotny
authors.forename: Frithjof
authors.initials: F
authors.lastname: Wickrath
authors.forename: Guido
authors.initials: G
authors.lastname: Giani
authors.forename: Jürgen
authors.initials: J
authors.lastname: Bunke
authors.forename: Michael
authors.initials: M
authors.lastname: Roden
authors.forename: Jong-Hee
authors.initials: JH
authors.lastname: Hwang
mesh_terms: D015331:Cohort Studies; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008099:Liver / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010710:Phosphates / Q000378:metabolism*; D010759:Phosphorus Isotopes / Q000493:pharmacokinetics; D066244:Proton Magnetic Resonance Spectroscopy / Q000295:instrumentation* / Q000379:methods*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D010710:Phosphates; D010759:Phosphorus Isotopes; D019275:Radiopharmaceuticals
keywords: 31P MRS; 3T clinical scanner; human liver; molar quantification; phosphorus compounds